The present invention relates to a processing solution circulating device to be provided in a film processor so as to facilitate replacement of the processing solution, such as developer. An exposed photographic film is treated through several steps, such as developing, stopping, fixing, washing and drying automatically in sequence, in a film processor. This invention relates particularly a processing solution circulating device for a continuous transfer type film processor in which a film is transfered continuously through the foregoing processes, and respective processings are performed during the transfer, and the film is discharged after a series of the processes. That is, this invention is applicable to a film processor of such type that the respective processings of development, fixing and washing are carried out by passing an exposed film through the processing solutions respectively supplied to the processing trays.
This type of film processor has been generally composed of four processing trays and a transfer mechanism thereto. The trays are arranged in parallel, and used as the developing, fixing, first washing and second washing trays in order from the insertion side of films, where a stop solution tray can be located between the developing tray and the fixing tray, if necessary, and also a drying equipment can be installed at the back of the second washing tray. The transfer mechanism is provided thereto to feed films from the inlet through the foregoing processes one after another, and to discharge the films from the outlet.
Ordinarily, several kinds of processing solutions have to be used depending on the type of the film to be processed. For example, a processing solution used for a high contrast lithtype film which is developed in a striking between black and white is different from one used for a continuous tone film of a regular contrast which is developed in continuous shading from white to black. Prior to treatments for a film, therefore, the processing solution to be supplied in the developing tray, i.e. the developer must be changed suitably to each type of films.
Wash-off type films are treated only through two processings, developing by the solution mixed with activator and washing, in place of the developing, stopping, fixing, first washing and second washing for ordinary films. For wash-off type films, therefore, it is necessary to supply a solution mixed with activator to the first washing tray used for processing of ordinary films so as the film is transfered directly to the activator processing tray in which the film is developed while skipping over the processes of developing, stopping and fixing of the film processor. Therefore, the processing solution must be replaced if a film processor is used for processing of ordinary films and also of wash-off type films.
Replacement of processing solutions has so far been made through the following procedure primarily by hands: discharging of processing solution through a drain pipe attached to the bottom of a processing tray to be retrieved into the first container in which the processing solution is stocked for future use, taking the container out of the film processor, washing off the tray after placing the second container into which the waste water is retrieved, and replacing the second container with the third container containing another processing solution.
The wash-off type films mentioned above have become popular and been applied in many fields because of simplicity in operation. Replacement of the washing water to be supplied into the first washing tray with the activator processing solution which is utilized for the wash-off type films, however, has be made frequently, in addition to the exchanging operations of trays. As the necessity of utilizing wash-off type films increases, replacement of processing solutions for film processor as described above becomes more frequent.